The invention relates to a surgical microscope for observing an infrared fluorescence and a microscopy method for observing an infrared fluorescence.
Fluorescent dyes are used in medical applications and biology for various purposes, such as visualizing particular types of tissue, tissue structures, tissue functions, tissue perfusion and other purposes. Herein, a fluorescent dye or a precursor of such fluorescent dye is applied to a tissue sample or a patient under examination. The dye or the precursor, respectively, accumulates in particular types of tissue and tissue structures of the tissue sample or the patient, respectively. The tissue may be illuminated with excitation light for exciting a fluorescence, and fluorescence light produced herein due to fluorescence occurring in the fluorescent dye may be detected so as to visualize particular tissue structures, types of tissue and tissue perfusion. A surgical microscope can be used to illuminate an object with excitation light and to detect fluorescence light.
A conventional surgical microscope comprises a first camera system for obtaining normal light images of an object, and a second camera system for obtaining fluorescence light images of the object.
One example of a fluorescent dye is indocyanine green (ICG) having a fluorescence spectrum in the range of infrared light.